Tea
Iced tea and cold brewing leaves
Two methods, one of which produces something considerably better than the other, and neither involves brewing hot and adding ice.
Most iced tea is made by brewing hot tea and pouring it over ice, which dilutes it and dulls it.
Two better approaches exist.
Cold brewing
Tea leaves steeped in cold water in the refrigerator for several hours.
The chemistry is the point. At low temperatures, catechins and caffeine extract slowly and incompletely, while amino acids including theanine — which carry sweetness and umami — extract relatively well.
The result is a tea that is markedly sweeter, smoother and less astringent than the same leaf brewed hot, with less caffeine.
The method. Roughly ten grams of leaf per litre of cold water. Steep in the refrigerator for six to twelve hours. Strain.
Green teas, particularly Japanese sencha and gyokuro, are transformed by this. So are lighter oolongs and white teas.
Black teas work and lose some of their briskness.
Keep refrigerated and drink within two or three days.
Flash chilling
The alternative, and the better method when you want the aromatic intensity of a hot brew.
Brew at double strength directly onto ice, so the tea is chilled instantly and the melting ice provides the remaining water.
The method. Fill a vessel with the amount of ice equal to half your target volume. Brew tea using half your target volume of hot water, at double the normal leaf quantity. Pour the hot tea directly over the ice.
The rapid chilling preserves aromatic compounds that would otherwise dissipate, and prevents the cloudiness that develops when hot tea cools slowly.
This is the standard method for iced coffee too, where it is called Japanese iced coffee, and the reasoning is identical.
Why slowly cooled tea goes cloudy
Tea cream — a haze that forms as tea cools — is caused by polyphenols and caffeine binding together and coming out of solution.
It is harmless and it looks unappealing and slightly dulls the flavour.
Rapid chilling largely prevents it. So does cold brewing, since the compounds never fully dissolve in the first place.
If it does happen, a small amount of hot water or lemon juice will generally clear it.
Which teas suit which method
Cold brew: Japanese greens, white teas, lighter oolongs, and delicate florals. The method flatters subtlety.
Flash chill: black teas, roasted oolongs, and anything where you want brisk aromatic intensity.
Either: herbal infusions, though hibiscus and fruit blends extract slowly cold and benefit from a longer steep.
Sweetening
Sugar does not dissolve well in cold liquid.
Make a simple syrup — equal parts sugar and water, heated until dissolved, cooled — and add to taste. It integrates properly.
Honey, similarly, is better dissolved in a little warm water first.
Cold-brewed tea frequently needs no sweetening at all, which is one of its virtues.
Additions worth trying
Fresh mint with green tea. Lemon with black tea, added at serving rather than during brewing. Ginger with black or oolong. Peach or stone fruit with white tea. Citrus peel.
Add aromatics for the last portion of a cold brew rather than the whole steep, since some become bitter over many hours.
The practical routine
Cold brew is the low-effort option: leaves and water in a jug, in the fridge overnight, strained in the morning.
A litre lasts a couple of days and requires no attention.
Flash chilling is for when you want a single glass and want it to be aromatic and bright.
Both beat hot tea poured over ice, which is what almost everyone does.
Keeping and serving
Cold-brewed tea keeps refrigerated for two or three days before it flattens and, with fruit or herbal additions, begins to ferment slowly.
Make it in quantities you will finish, and strain the leaves out completely rather than leaving them in the jug — extraction continues slowly even cold, and by day two an unstrained brew is unpleasantly tannic.
Serve over fresh ice rather than storing it with ice, which dilutes it as it melts in the fridge.
If you want it colder without dilution, freeze some of the brewed tea into cubes and use those.
For flash-chilled tea, drink it within a few hours. The aromatic intensity that justifies the method fades faster than the tea itself.
A note on commercial iced tea
Bottled iced tea is generally made from extract, heavily sweetened, and bears little relation to brewed tea.
Reading the sugar content is instructive — many contain quantities comparable to soft drinks.
Home-brewed iced tea costs a fraction and tastes like tea.
